Glaucoma stent and methods thereof for glaucoma treatment

ABSTRACT

The invention relates generally to medical devices and methods for reducing the intraocular pressure in an animal eye and, more particularly, to stent type devices for permitting aqueous outflow from the eye&#39;s anterior chamber and associated methods thereof for the treatment of glaucoma. Some aspects provide a self-trephining glaucoma stent and methods thereof which advantageously allow for a “one-step” procedure in which the incision and placement of the stent are accomplished by a single device and operation. This desirably allows for a faster, safer, and less expensive surgical procedure.

RELATED APPLICATION

This application is a continuation application of U.S. patentapplication Ser. No. 14/207,240 filed Mar. 12, 2014, now U.S. Pat. No.10,517,759, titled GLAUCOMA STENT AND METHODS THEREOF FOR GLAUCOMATREATMENT, which claims priority benefit of U.S. Provisional ApplicationNo. 61/794,832 filed Mar. 15, 2013, titled GLAUCOMA STENT AND METHODSTHEREOF FOR GLAUCOMA TREATMENT, the entire contents of which isincorporated herein by reference.

BACKGROUND OF THE INVENTION Field of the Invention

The invention relates generally to medical devices and methods forreducing the intraocular pressure in an animal eye and, moreparticularly, to shunt type devices for permitting aqueous outflow fromthe eye's anterior chamber and associated methods thereof for thetreatment of glaucoma.

Description of the Related Art

The human eye is a specialized sensory organ capable of light receptionand able to receive visual images. The trabecular meshwork serves as adrainage channel and is located in anterior chamber angle formed betweenthe iris and the cornea. The trabecular meshwork maintains a balancedpressure in the anterior chamber of the eye by draining aqueous humorfrom the anterior chamber.

About two percent of people in the United States have glaucoma. Glaucomais a group of eye diseases encompassing a broad spectrum of clinicalpresentations, etiologies, and treatment modalities. Glaucoma causespathological changes in the optic nerve, visible on the optic disk, andit causes corresponding visual field loss, resulting in blindness ifuntreated. Lowering intraocular pressure is the major treatment goal inall glaucomas.

In glaucomas associated with an elevation in eye pressure (intraocularhypertension), the source of resistance to outflow is mainly in thetrabecular meshwork. The tissue of the trabecular meshwork allows theaqueous humor (“aqueous”) to enter Schlemm's canal, which then emptiesinto aqueous collector channels in the posterior wall of Schlemm's canaland then into aqueous veins, which form the episcleral venous system.Aqueous humor is a transparent liquid that fills the region between thecornea, at the front of the eye, and the lens. The aqueous humor iscontinuously secreted by the ciliary body around the lens, so there is aconstant flow of aqueous humor from the ciliary body to the eye's frontchamber. The eye's pressure is determined by a balance between theproduction of aqueous and its exit through the trabecular meshwork(major route) or uveal scleral outflow (minor route). The trabecularmeshwork is located between the outer rim of the iris and the back ofthe cornea, in the anterior chamber angle. The portion of the trabecularmeshwork adjacent to Schlemm's canal (the juxtacanilicular meshwork)causes most of the resistance to aqueous outflow.

Glaucoma is grossly classified into two categories: closed-angleglaucoma, also known as angle closure glaucoma, and open-angle glaucoma.Closed-angle glaucoma is caused by closure of the anterior chamber angleby contact between the iris and the inner surface of the trabecularmeshwork. Closure of this anatomical angle prevents normal drainage ofaqueous humor from the anterior chamber of the eye.

Open-angle glaucoma is any glaucoma in which the angle of the anteriorchamber remains open, but the exit of aqueous through the trabecularmeshwork is diminished. The exact cause for diminished filtration isunknown for most cases of open-angle glaucoma. Primary open-angleglaucoma is the most common of the glaucomas, and it is oftenasymptomatic in the early to moderately advanced stage. Patients maysuffer substantial, irreversible vision loss prior to diagnosis andtreatment. However, there are secondary open-angle glaucomas which mayinclude edema or swelling of the trabecular spaces (e.g., fromcorticosteroid use), abnormal pigment dispersion, or diseases such ashyperthyroidism that produce vascular congestion.

Current therapies for glaucoma are directed at decreasing intraocularpressure. Medical therapy includes topical ophthalmic drops or oralmedications that reduce the production or increase the outflow ofaqueous. However, these drug therapies for glaucoma are sometimesassociated with significant side effects, such as headache, blurredvision, allergic reactions, death from cardiopulmonary complications,and potential interactions with other drugs. When drug therapy fails,surgical therapy is used. Surgical therapy for open-angle glaucomaconsists of laser trabeculoplasty, trabeculectomy, and implantation ofaqueous shunts after failure of trabeculectomy or if trabeculectomy isunlikely to succeed. Trabeculectomy is a major surgery that is widelyused and is augmented with topically applied anticancer drugs, such as5-flurouracil or mitomycin-C to decrease scarring and increase thelikelihood of surgical success.

Approximately 100,000 trabeculectomies are performed on Medicare-agepatients per year in the United States. This number would likelyincrease if the morbidity associated with trabeculectomy could bedecreased. The current morbidity associated with trabeculectomy consistsof failure (10-15%); infection (a lifelong risk of 2-5%); choroidalhemorrhage, a severe internal hemorrhage from low intraocular pressure,resulting in visual loss (1%); cataract formation; and hypotonymaculopathy (potentially reversible visual loss from low intraocularpressure).

For these reasons, surgeons have tried for decades to develop a workablesurgery for the trabecular meshwork.

The surgical techniques that have been tried and practiced aregoniotomy/trabeculotomy and other mechanical disruptions of thetrabecular meshwork, such as trabeculopuncture, goniophotoablation,laser trabecular ablation, and goniocurretage. These are all majoroperations and are briefly described below.

Goniotomy/Trabeculotomy: Goniotomy and trabeculotomy are simple anddirected techniques of microsurgical dissection with mechanicaldisruption of the trabecular meshwork. These initially had earlyfavorable responses in the treatment of open-angle glaucoma. However,long-term review of surgical results showed only limited success inadults. In retrospect, these procedures probably failed due to cellularrepair and fibrosis mechanisms and a process of “filling in.” Filling inis a detrimental effect of collapsing and closing in of the createdopening in the trabecular meshwork. Once the created openings close, thepressure builds back up and the surgery fails.

Trabeculopuncture: Q-switched Neodynium (Nd) YAG lasers also have beeninvestigated as an optically invasive technique for creatingfull-thickness holes in trabecular meshwork. However, the relativelysmall hole created by this trabeculopuncture technique exhibits afilling-in effect and fails.

Goniophotoablation/Laser Trabecular Ablation: Goniophotoablation isdisclosed by Berlin in U.S. Pat. No. 4,846,172 and involves the use ofan excimer laser to treat glaucoma by ablating the trabecular meshwork.This was demonstrated not to succeed by clinical trial. Hill et al. usedan Erbium:YAG laser to create full-thickness holes through trabecularmeshwork (Hill et al., Lasers in Surgery and Medicine 11:341-346, 1991).This technique was investigated in a primate model and a limited humanclinical trial at the University of California, Irvine. Althoughmorbidity was zero in both trials, success rates did not warrant furtherhuman trials. Failure was again from filling in of surgically createddefects in the trabecular meshwork by repair mechanisms. Neither ofthese is a viable surgical technique for the treatment of glaucoma.

Goniocurretage: This is an ab interno (from the inside), mechanicallydisruptive technique that uses an instrument similar to a cyclodialysisspatula with a microcurrette at the tip. Initial results were similar totrabeculotomy: it failed due to repair mechanisms and a process offilling in.

Although trabeculectomy is the most commonly performed filteringsurgery, viscocanulostomy (VC) and non penetrating trabeculectomy (NPT)are two new variations of filtering surgery. These are ab externo (fromthe outside), major ocular procedures in which Schlemm's canal issurgically exposed by making a large and very deep scleral flap. In theVC procedure, Schlemm's canal is cannulated and viscoelastic substanceinjected (which dilates Schlemm's canal and the aqueous collectorchannels). In the NPT procedure, the inner wall of Schlemm's canal isstripped off after surgically exposing the canal.

Trabeculectomy, VC, and NPT involve the formation of an opening or holeunder the conjunctiva and scleral flap into the anterior chamber, suchthat aqueous humor is drained onto the surface of the eye or into thetissues located within the lateral wall of the eye. These surgicaloperations are major procedures with significant ocular morbidity. Whentrabeculectomy, VC, and NPT are thought to have a low chance forsuccess, a number of implantable drainage devices have been used toensure that the desired filtration and outflow of aqueous humor throughthe surgical opening will continue. The risk of placing a glaucomadrainage device also includes hemorrhage, infection, and diplopia(double vision).

Examples of implantable shunts and surgical methods for maintaining anopening for the release of aqueous humor from the anterior chamber ofthe eye to the sclera or space beneath the conjunctiva have beendisclosed in, for example, U.S. Pat. No. 6,059,772 to Hsia et al., andU.S. Pat. No. 6,050,970 to Baerveldt.

All of the above surgeries and variations thereof have numerousdisadvantages and moderate success rates. They involve substantialtrauma to the eye and require great surgical skill in creating a holethrough the full thickness of the sclera into the subconjunctival space.The procedures are generally performed in an operating room and have aprolonged recovery time for vision.

The complications of existing filtration surgery have promptedophthalmic surgeons to find other approaches to lowering intraocularpressure.

The trabecular meshwork and juxtacanilicular tissue together provide themajority of resistance to the outflow of aqueous and, as such, arelogical targets for surgical removal in the treatment of open-angleglaucoma. In addition, minimal amounts of tissue are altered andexisting physiologic outflow pathways are utilized.

As reported in Arch. Ophthalm. (2000) 118:412, glaucoma remains aleading cause of blindness, and filtration surgery remains an effective,important option in controlling the disease. However, modifying existingfiltering surgery techniques in any profound way to increase theireffectiveness appears to have reached a dead end. The article furtherstates that the time has come to search for new surgical approaches thatmay provide better and safer care for patients with glaucoma.

Therefore, there is a great clinical need for a method of treatingglaucoma that is faster, safer, and less expensive than currentlyavailable modalities.

SUMMARY OF THE INVENTION

The trabecular meshwork and juxtacanilicular tissue together provide themajority of resistance to the outflow of aqueous and, as such, arelogical targets for surgical approach in the treatment of glaucoma.Various embodiments of glaucoma shunts are disclosed herein for aqueousto exit through the trabecular meshwork (major route) or uveal scleraloutflow (minor route) or other route effective to reduce intraocularpressure (IOP).

Glaucoma surgical morbidity would greatly decrease if one were to bypassthe focal resistance to outflow of aqueous only at the point ofresistance, and to utilize remaining, healthy aqueous outflowmechanisms. This is in part because episcleral aqueous humor exerts abackpressure that prevents intraocular pressure from going too low, andone could thereby avoid hypotony. Thus, such a surgery would virtuallyeliminate the risk of hypotony-related maculopathy and choroidalhemorrhage. Furthermore, visual recovery would be very rapid, and therisk of infection would be very small, reflecting a reduction inincidence from 2-5% to about 0.05%.

U.S. Pat. No. 6,638,239, filed Apr. 14, 2000, entitled APPARATUS ANDMETHOD FOR TREATING GLAUCOMA, and U.S. Pat. No. 6,736,791, filed Nov. 1,2000, entitled GLAUCOMA TREATMENT DEVICE, disclose devices and methodsof placing a trabecular shunt ab interno, i.e., from inside the anteriorchamber through the trabecular meshwork, into Schlemm's canal. Theentire contents of each one of these copending patent applications arehereby incorporated by reference herein. The invention encompasses bothab interno and ab externo glaucoma shunts or stents and methods thereof.

Techniques performed in accordance with aspects herein may be referredto generally as “trabecular bypass surgery.” Advantages of this type ofsurgery include lowering intraocular pressure in a manner which issimple, effective, disease site-specific, and can potentially beperformed on an outpatient basis.

Generally, trabecular bypass surgery (TBS) creates an opening, a slit,or a hole through trabecular meshwork with minor microsurgery. TBS hasthe advantage of a much lower risk of choroidal hemorrhage and infectionthan prior techniques, and it uses existing physiologic outflowmechanisms. In some aspects, this surgery can potentially be performedunder topical or local anesthesia on an outpatient basis with rapidvisual recovery. To prevent “filling in” of the hole, a biocompatibleelongated device is placed within the hole and serves as a stent. U.S.Pat. No. 6,638,239, filed Apr. 14, 2000, the entire contents of whichare hereby incorporated by reference herein, discloses trabecular bypasssurgery.

As described in U.S. Pat. No. 6,638,239, filed Apr. 14, 2000, and U.S.Pat. No. 6,736,791, filed Nov. 1, 2000, the entire contents each one ofwhich are hereby incorporated by reference herein, a trabecular shunt orstent for transporting aqueous humor is provided. The trabecular stentincludes a hollow, elongate tubular element, having an inlet section andan outlet section. The outlet section may optionally include twosegments or elements, adapted to be positioned and stabilized insideSchlemm's canal. In one embodiment, the device appears as a “T” shapeddevice.

In one aspect of the invention, a delivery apparatus (or “applicator”)is used for placing a trabecular stent through a trabecular meshwork ofan eye. Certain embodiments of such a delivery apparatus are disclosedin U.S. application Ser. No. 10/101,548, filed Mar. 18, 2002, entitledAPPLICATOR AND METHODS FOR PLACING A TRABECULAR SHUNT FOR GLAUCOMATREATMENT, and U.S. Provisional Application No. 60/276,609, filed Mar.16, 2001, entitled APPLICATOR AND METHODS FOR PLACING A TRABECULAR SHUNTFOR GLAUCOMA TREATMENT, the entire contents of each one of which arehereby incorporated by reference herein.

The stent has an inlet section and an outlet section. The deliveryapparatus includes a handpiece, an elongate tip, a holder and anactuator. The handpiece has a distal end and a proximal end. Theelongate tip is connected to the distal end of the handpiece. Theelongate tip has a distal portion and is configured to be placed througha corneal incision and into an anterior chamber of the eye. The holderis attached to the distal portion of the elongate tip. The holder isconfigured to hold and release the inlet section of the trabecularstent. The actuator is on the handpiece and actuates the holder torelease the inlet section of the trabecular stent from the holder. Whenthe trabecular stent is deployed from the delivery apparatus into theeye, the outlet section is positioned in substantially oppositedirections inside Schlemm's canal. In one embodiment, a deploymentmechanism within the delivery apparatus includes a push-pull typeplunger.

Some aspects of the invention relate to devices for reducing intraocularpressure by providing outflow of aqueous from an anterior chamber of aneye. The device generally comprises an elongated tubular member andcutting means. The tubular member is adapted for extending through atrabecular meshwork of the eye. The tubular member generally comprises alumen having an inlet port and an outlet port for providing a flowpathway. The cutting means is mechanically connected to the tubularmember for creating an incision in the trabecular meshwork for receivingat least a portion of the tubular member.

In one aspect, a self-trephining glaucoma stent is provided for reducingand/or balancing intraocular pressure in an eye. The stent generallycomprises a snorkel and a curved blade. The snorkel generally comprisesan upper seat for stabilizing said stent within the eye, a shank and alumen. The shank is mechanically connected to the seat and is adaptedfor extending through a trabecular meshwork of the eye. The lumenextends through the snorkel and has at least one inlet flow port and atleast one outlet flow port. The blade is mechanically connected to thesnorkel. The blade generally comprises a cutting tip proximate adistal-most point of the blade for making an incision in the trabecularmeshwork for receiving the shank.

Some aspects of the invention relate to methods of implanting atrabecular stent device in an eye. In one aspect, the device has asnorkel mechanically connected to a blade. The blade is advanced bladethrough a trabecular meshwork of the eye to cut the trabecular meshworkand form an incision therein. At least a portion of the snorkel isinserted in the incision to implant the device in the eye.

Some aspects provide a self-trephining glaucoma stent and methodsthereof which advantageously allow for a “one-step” procedure in whichthe incision and placement of the stent are accomplished by a singledevice and operation. This desirably allows for a faster, safer, andless expensive surgical procedure. In any of the embodiments, fiducialmarkings, indicia, or the like and/or positioning of the stent device ina preloaded applicator may be used for proper orientation and alignmentof the device during implantation.

Among the advantages of trabecular bypass surgery is its simplicity. Themicrosurgery may potentially be performed on an outpatient basis withrapid visual recovery and greatly decreased morbidity. There is a lowerrisk of infection and choroidal hemorrhage, and there is a fasterrecovery, than with previous techniques.

For purposes of summarizing the invention, certain aspects, advantagesand novel features of the invention have been described herein above. Ofcourse, it is to be understood that not necessarily all such advantagesmay be achieved in accordance with any particular embodiment of theinvention. Thus, the invention may be embodied or carried out in amanner that achieves or optimizes one advantage or group of advantagesas taught or suggested herein without necessarily achieving otheradvantages as may be taught or suggested herein.

All of these embodiments are intended to be within the scope of theinvention herein disclosed. These and other embodiments of the inventionwill become readily apparent to those skilled in the art from thefollowing detailed description of the preferred embodiments havingreference to the attached figures, the invention not being limited toany particular preferred embodiment(s) disclosed.

BRIEF DESCRIPTION OF THE DRAWINGS

Having thus summarized the general nature of the invention and some ofits features and advantages, certain preferred embodiments andmodifications thereof will become apparent to those skilled in the artfrom the detailed description herein having reference to the figuresthat follow, of which:

FIG. 1 is a coronal cross-sectional view of an eye;

FIG. 2 is an enlarged cross-sectional view of an anterior chamber angleof the eye of FIG. 1 ;

FIG. 3 is a simplified partial view of an eye illustrating theimplantation of a glaucoma stent having features and advantages inaccordance with one embodiment of the invention;

FIG. 4 is a side elevation view of the stent of FIG. 3 ;

FIG. 5 is a top plan view of the stent of FIG. 3 ;

FIG. 6 is a bottom plan view of the stent of FIG. 3 ;

FIG. 7 is a front end view of the stent of FIG. 3 (along line 7-7 ofFIG. 4 );

FIG. 8 is a rear end view of the stent of FIG. 3 (along line 8-8 of FIG.4 );

FIG. 9 is an enlarged top plan view of a cutting tip of the stent ofFIG. 3 ;

FIG. 10 is a top plan view of one exemplary embodiment of a snorkel topseating surface;

FIG. 11 is a top plan view of another exemplary embodiment of a snorkeltop seating surface;

FIG. 12 is a top plan view of yet another exemplary embodiment of asnorkel top seating surface;

FIG. 13 is a top plan view of still another exemplary embodiment of asnorkel top seating surface;

FIG. 14 is a simplified partial view of an eye illustrating theimplantation of a glaucoma stent having features and advantages inaccordance with another embodiment of the invention;

FIG. 15 is a simplified partial view of an eye illustrating theimplantation of a glaucoma stent having features and advantages inaccordance with a further embodiment of the invention;

FIG. 16 is a side elevation view of a glaucoma stent having features andadvantages in accordance with one embodiment of the invention;

FIG. 17 is a top plan view of the stent of FIG. 16 ;

FIG. 18 is a bottom plan view of the stent of FIG. 16 ;

FIG. 19 is a front end view along line 19-19 of FIG. 16 ;

FIG. 20 is a rear end view along line 20-20 of FIG. 16 ;

FIG. 21 is a side elevation view of a glaucoma stent having features andadvantages in accordance with one embodiment of the invention;

FIG. 22 is a top plan view of the stent of FIG. 21 ;

FIG. 23 is a bottom plan view of the stent of FIG. 21 ;

FIG. 24 is a front end view along line 24-24 of FIG. 21 ;

FIG. 25 is a rear end view along line 25-25 of FIG. 21 ;

FIG. 26 is a front elevation view of a glaucoma stent having featuresand advantages in accordance with one embodiment of the invention;

FIG. 27 is a side elevation view along line 27-27 of FIG. 26 ;

FIG. 28 is a rear end view along line 28-28 of FIG. 26 ;

FIG. 29 is a simplified partial view of an eye illustrating the temporalimplantation of a glaucoma stent using a delivery apparatus havingfeatures and advantages in accordance with one embodiment of theinvention;

FIG. 30 is an oblique elevational view of an articulating arm stentdelivery/retrieval apparatus having features and advantages inaccordance with one embodiment of the invention;

FIG. 31 is a simplified partial view of an eye illustrating theimplantation of a glaucoma stent using a delivery apparatus crossingthrough the eye anterior chamber;

FIG. 32 is a simplified partial view of an eye illustrating theimplantation of a glaucoma stent having features and advantages inaccordance with one embodiment of the invention;

FIG. 33 is a detailed enlarged view of the barbed pin of FIG. 32 ;

FIG. 34 is a simplified partial view of an eye illustrating theimplantation of a glaucoma stent having features and advantages inaccordance with one embodiment of the invention;

FIG. 35 is a simplified partial view of an eye illustrating theimplantation of a glaucoma stent having features and advantages inaccordance with one embodiment of the invention;

FIG. 36A is a simplified partial view of an eye illustrating theimplantation of a glaucoma stent having features and advantages inaccordance with one embodiment of the invention;

FIG. 36B is a side elevation view of a glaucoma stent having featuresand advantages in accordance with one embodiment of the invention;

FIG. 36C is a perspective view of the stent of FIG. 36B;

FIG. 36D is a side elevation view of a glaucoma stent having featuresand advantages in accordance with one embodiment of the invention;

FIG. 36E is a perspective view of the stent of FIG. 36D;

FIG. 36F is a another perspective view of the stent of FIG. 36D;

FIG. 36G is a side elevation view of a glaucoma stent having featuresand advantages in accordance with one embodiment of the invention;

FIG. 36H is a perspective view of the stent of FIG. 36G;

FIG. 36I is a another perspective view of the stent of FIG. 36G;

FIG. 36J is a side elevation view of a glaucoma stent having featuresand advantages in accordance with one embodiment of the invention;

FIG. 36K is a perspective view of the stent of FIG. 36J;

FIG. 37 is a simplified partial view of an eye illustrating theimplantation of a glaucoma stent having features and advantages inaccordance with one embodiment of the invention;

FIG. 38 is a simplified partial view of an eye illustrating theimplantation of a glaucoma stent having features and advantages inaccordance with one embodiment of the invention;

FIG. 39 is a simplified partial view of an eye illustrating theimplantation of a glaucoma stent having features and advantages inaccordance with one embodiment of the invention;

FIG. 40 is a simplified partial view of an eye illustrating theimplantation of a glaucoma stent having features and advantages inaccordance with one embodiment of the invention;

FIG. 41 is a simplified partial view of an eye illustrating theimplantation of a glaucoma stent having features and advantages inaccordance with one embodiment of the invention;

FIG. 42 is a simplified partial view of an eye illustrating theimplantation of a glaucoma stent having features and advantages inaccordance with one embodiment of the invention;

FIG. 43 is a simplified partial view of an eye illustrating theimplantation of a valved tube stent device having features andadvantages in accordance with one embodiment of the invention;

FIG. 44 is a simplified partial view of an eye illustrating theimplantation of an osmotic membrane device having features andadvantages in accordance with one embodiment of the invention;

FIG. 45 is a simplified partial view of an eye illustrating theimplantation of a glaucoma stent using ab externo procedure havingfeatures and advantages in accordance with one embodiment of theinvention;

FIG. 46 is a simplified partial view of an eye illustrating theimplantation of a glaucoma stent having features and advantages inaccordance with a modified embodiment of the invention; and

FIG. 47 is a simplified partial view of an eye illustrating theimplantation of a drug release implant having features and advantages inaccordance with one embodiment of the invention.

FIG. 48 is an oblique elevational view of a trabecular shunt applicatorwith a retractable blade mechanism.

FIGS. 49A and 49B are schematic cross sections of a trabecular punchdevice.

FIGS. 50A and 50B are elevational views of a control arm andtrabeculotomy device for the trabecular shunt applicator.

FIGS. 51A through 51C are schematic oblique elevational views of varioustrabecular meshwork punching and drilling devices.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

The preferred embodiments of the invention described herein relateparticularly to surgical and therapeutic treatment of glaucoma throughreduction of intraocular pressure. While the description sets forthvarious embodiment specific details, it will be appreciated that thedescription is illustrative only and should not be construed in any wayas limiting the invention. Furthermore, various applications of theinvention, and modifications thereto, which may occur to those who areskilled in the art, are also encompassed by the general conceptsdescribed herein.

FIG. 1 is a cross-sectional view of an eye 10, while FIG. 2 is aclose-up view showing the relative anatomical locations of a trabecularmeshwork 21, an anterior chamber 20, and a Schlemm's canal 22. A sclera11 is a thick collagenous tissue which covers the entire eye 10 except aportion which is covered by a cornea 12.

Referring to FIGS. 1 and 2 , the cornea 12 is a thin transparent tissuethat focuses and transmits light into the eye and through a pupil 14,which is a circular hole in the center of an iris 13 (colored portion ofthe eye). The cornea 12 merges into the sclera 11 at a juncture referredto as a limbus 15. A ciliary body 16 extends along the interior of thesclera 11 and is coextensive with a choroid 17. The choroid 17 is avascular layer of the eye 10, located between the sclera 11 and a retina18. An optic nerve 19 transmits visual information to the brain and isthe anatomic structure that is progressively destroyed by glaucoma.

Still referring to FIGS. 1 and 2 , the anterior chamber 20 of the eye10, which is bound anteriorly by the cornea 12 and posteriorly by theiris 13 and a lens 26, is filled with aqueous humor (hereinafterreferred to as “aqueous”). Aqueous is produced primarily by the ciliarybody 16, then moves anteriorly through the pupil 14 and reaches ananterior chamber angle 25, formed between the iris 13 and the cornea 12.

As best illustrated by the drawing of FIG. 2 , in a normal eye, aqueousis removed from the anterior chamber 20 through the trabecular meshwork21. Aqueous passes through the trabecular meshwork 21 into Schlemm'scanal 22 and thereafter through a plurality of aqueous veins 23, whichmerge with blood-carrying veins, and into systemic venous circulation.Intraocular pressure is maintained by an intricate balance betweensecretion and outflow of aqueous in the manner described above. Glaucomais, in most cases, characterized by an excessive buildup of aqueous inthe anterior chamber 20 which leads to an increase in intraocularpressure. Fluids are relatively incompressible, and thus intraocularpressure is distributed relatively uniformly throughout the eye 10.

As shown in FIG. 2 , the trabecular meshwork 21 is adjacent a smallportion of the sclera 11. Exterior to the sclera 11 is a conjunctiva 24.Traditional procedures that create a hole or opening for implanting adevice through the tissues of the conjunctiva 24 and sclera 11 involveextensive surgery, as compared to surgery for implanting a device, asdescribed herein, which ultimately resides entirely within the confinesof the sclera 11 and cornea 12.

Self-Trephining Glaucoma Stent

FIG. 3 generally illustrates the use of one embodiment of a trabecularstenting device 30 for establishing an outflow pathway, passing throughthe trabecular meshwork 21, which is discussed in greater detail below.FIGS. 4-9 are different views of the stent 30. Advantageously, and asdiscussed in further detail later herein, the self-trephining-stentallows a one-step procedure to make an incision in the trabecular mesh21 and place the stent or implant 30 at the desired or predeterminedposition within the eye 10. Desirably, this facilitates the overallsurgical procedure.

In the illustrated embodiment of FIGS. 3-9 , the shunt or stent 30generally comprises a snorkel 32 and a main body portion or blade 34.The snorkel 32 and blade 34 are mechanically connected to or inmechanical communication with one another. The stent 30 and/or the bodyportion 34 have a generally longitudinal axis 36.

In the illustrated embodiment of FIGS. 3-9 , the stent 30 comprises anintegral unit. In modified embodiments, the stent 30 may comprise anassembly of individual pieces or components. For example, the stent 30may comprise an assembly of the snorkel 32 and blade 34.

In the illustrated embodiment of FIGS. 3-9 , the snorkel 32 is in theform of a generally elongate tubular member and generally comprises anupper seat, head or cap portion 38, a shank portion 40 and a lumen orpassage 42 extending therethrough. The seat 38 is mechanically connectedto or in mechanical communication with the shank 40 which is alsomechanically connected to or in mechanical communication with the blade34. The snorkel 32 and/or the lumen 42 have a generally longitudinalaxis 43.

In the illustrated embodiment of FIGS. 3-9 , the seat 38 is generallycircular in shape and has an upper surface 44 and a lower surface 46which, as shown in FIG. 3 , abuts or rests against the trabecularmeshwork 21 to stabilize the glaucoma stent 30 within the eye 10. Inmodified embodiments, the seat 38 may efficaciously be shaped in othersuitable manners, as required or desired, giving due consideration tothe goals of stabilizing the glaucoma stent 30 within the eye 10 and/orof achieving one or more of the benefits and advantages as taught orsuggested herein. For example, the seat 38 may be shaped in otherpolygonal or non-polygonal shapes and/or comprise one or more ridgeswhich extend radially outwards, among other suitable retention devices.

In the illustrated embodiment of FIGS. 3-9 , and as best seen in the topview of FIG. 5 , the seat top surface 44 comprises fiducial marks orindicia 48. These marks or indicia 48 facilitate and ensure properorientation and alignment of the stent 30 when implanted in the eye 10.The marks or indicia 48 may comprise visual differentiation means suchas color contrast or be in the form of ribs, grooves, or the like.Alternatively, or in addition, the marks 48 may provide tactile sensoryfeedback to the surgeon. Also, the seat 38 and/or the seat top surface44 may be configured in predetermined shapes aligned with the blade 34and/or longitudinal axis 36 to provide for proper orientation of thestent device 30 within the eye 10. For example, the seat top surface 44may be oval or ellipsoidal (FIG. 10 ), rectangular (FIG. 11 ), hexagonal(FIG. 12 ), among other suitable shapes (e.g. FIG. 13 ).

In the illustrated embodiment of FIGS. 3-9 , and as indicated above, theseat bottom surface 46 abuts or rests against the trabecular meshwork 21to stabilize and retain the glaucoma stent 30 within the eye 10. Forstabilization purposes, the seat bottom surface 46 may comprise astubbed surface, a ribbed surface, a surface with pillars, a texturedsurface, or the like.

In the illustrated embodiment of FIGS. 3-9 , the snorkel shank 40 isgenerally cylindrical in shape. With the stent 30 implanted, as shown inFIG. 3 , the shank 40 is generally positioned in an incision or cavity50 formed in the trabecular meshwork 21 by the self-trephining stent 30.Advantageously, and as discussed further below, this single step offorming the cavity 50 by the stent 30 itself and placing the stent 30 inthe desired position facilitates and expedites the overall surgicalprocedure. In modified embodiments, the snorkel shank 40 mayefficaciously be shaped in other suitable manners, as required ordesired. For example, the shank 40 may be in the shape of otherpolygonal or non-polygonal shapes, such as, oval, elliposoidal, and thelike.

In the illustrated embodiment of FIGS. 3-9 , and as best seen in FIG. 3, the shank 40 has an outer surface 52 in contact with the trabecularmeshwork 21 surrounding the cavity 50. For stabilization purposes, theshank outer surface 52 may comprise a stubbed surface, a ribbed surface,a surface with pillars, a textured surface, or the like.

In the illustrated embodiment of FIGS. 3-9 , the snorkel lumen 42 has aninlet port, opening or orifice 54 at the seat top surface 44 and anoutlet port, opening or orifice 56 at the junction of the shank 40 andblade 34. The lumen 42 is generally cylindrical in shape, that is, ithas a generally circular cross-section, and its ports 54, 56 aregenerally circular in shape. In modified embodiments, the lumen 42 andports 54, 56 may be efficaciously shaped in other manners, as requiredor desired, giving due consideration to the goals of providingsufficient aqueous outflow and/or of achieving one or more of thebenefits and advantages as taught or suggested herein. For example, thelumen 42 and/or one or both ports 54, 56 may be shaped in the form ofovals, ellipsoids, and the like, or the lumen 42 may have a tapered orstepped configuration.

Referring in particular to FIG. 3 , aqueous from the anterior chamber 20flows into the lumen 42 through the inlet port 54 (as generallyindicated by arrow 58) and out of the outlet port 56 and into Schlemm'scanal 22 (as generally indicated by arrows 60) to lower and/or balancethe intraocular pressure (IOP). In another embodiment, as discussed infurther detail below, one or more of the outlet ports may be configuredto face in the general direction of the stent longitudinal axis 36. Inmodified embodiments, the snorkel 32 may comprise more than one lumen,as needed or desired, to facilitate multiple aqueous outflowtransportation into Schlemm's canal 22.

In the illustrated embodiment of FIGS. 3-9 , the blade longitudinal axis36 and the snorkel longitudinal axis 43 are generally perpendicular toone another. Stated differently, the projections of the axes 36, 43 on acommon plane which is not perpendicular to either of the axes 36, 43intersect at 90°. The blade longitudinal axis 36 and the snorkellongitudinal axis 43 may intersect one another or may be offset from oneanother.

In the illustrated embodiment of FIGS. 3-9 , the main body portion orblade 34 is a generally curved elongated sheet- or plate-like structurewith an upper curved surface 62 and a lower curved surface 64 whichdefines a trough or open face channel 66. The perimeter of the blade 34is generally defined by a curved proximal edge 68 proximate to thesnorkel 32, a curved distal edge 70 spaced from the proximal edge 68 bya pair of generally straight lateral edges 72, 74 with the first lateraledge 72 extending beyond the second lateral edge 74 and intersectingwith the distal edge 70 at a distal-most point 76 of the blade 34proximate a blade cutting tip 78.

In the illustrated embodiment of FIGS. 3-9 , and as shown in theenlarged view of FIG. 9 , the cutting tip 78 comprises a first cuttingedge 80 on the distal edge 70 and a second cutting edge 82 on thelateral edge 72. The cutting edges 80, 82 preferably extend from thedistal-most point 76 of the blade 34 and comprise at least a respectiveportion of the distal edge 70 and lateral edge 72. The respectivecutting edges 80, 82 are formed at the sharp edges of respective beveledor tapered surfaces 84, 86. In one embodiment, the remainder of thedistal edge 70 and lateral edge 72 are dull or rounded. In oneembodiment, the tip 78 proximate to the distal-most end 76 is curvedslightly inwards, as indicated generally by the arrow 88 in FIG. 5 andarrow 88 (pointed perpendicular and into the plane of the paper) in FIG.9 , relative to the adjacent curvature of the blade 34.

In modified embodiments, suitable cutting edges may be provided onselected portions of one or more selected blade edges 68, 70, 72, 74with efficacy, as needed or desired, giving due consideration to thegoals of providing suitable cutting means on the stent 30 foreffectively cutting through the trabecular meshwork 21 (FIG. 3 ) and/orof achieving one or more of the benefits and advantages as taught orsuggested herein.

Referring in particular to FIG. 9 , in one embodiment, the ratio betweenthe lengths of the cutting edges 80, 82 is about 2:1. In anotherembodiment, the ratio between the lengths of the cutting edges 80, 82 isabout 1:1. In yet another embodiment, the ratio between the lengths ofthe cutting edges 80, 82 is about 1:2. In modified embodiments, thelengths of the cutting edges 80, 82 may be efficaciously selected inother manners, as required or desired, giving due consideration to thegoals of providing suitable cutting means on the stent 30 foreffectively cutting through the trabecular meshwork 21 (FIG. 3 ) and/orof achieving one or more of the benefits and advantages as taught orsuggested herein.

Still referring in particular to FIG. 9 , in one embodiment, the ratiobetween the lengths of the cutting edges 80, 82 is in the range fromabout 2:1 to about 1:2. In another embodiment, the ratio between thelengths of the cutting edges 80, 82 is in the range from about 5:1 toabout 1:5. In yet another embodiment, the ratio between the lengths ofthe cutting edges 80, 82 is in the range from about 10:1 to about 1:10.In modified embodiments, the lengths of the cutting edges 80, 82 may beefficaciously selected in other manners, as required or desired, givingdue consideration to the goals of providing suitable cutting means onthe stent 30 for effectively cutting through the trabecular meshwork 21(FIG. 3 ) and/or of achieving one or more of the benefits and advantagesas taught or suggested herein.

As shown in the top view of FIG. 9 , the cutting edge 80 (and/or thedistal end 70) and the cutting edge 82 (and/or the lateral edge 72)intersect at an angle θ. Stated differently, θ is the angle between theprojections of the cutting edge 80 (and/or the distal end 70) and thecutting edge 82 (and/or the lateral edge 72) on a common plane which isnot perpendicular to either of these edges.

Referring to in particular to FIG. 9 , in one embodiment, the angle θ isabout 50°. In another embodiment, the angle θ is in the range from about40° to about 60°. In yet another embodiment, the angle θ is in the rangefrom about 30° to about 70°. In modified embodiments, the angle θ may beefficaciously selected in other manners, as required or desired, givingdue consideration to the goals of providing suitable cutting means onthe stent 30 for effectively cutting through the trabecular meshwork 21(FIG. 3 ) and/or of achieving one or more of the benefits and advantagesas taught or suggested herein.

The stent 30 of the embodiments disclosed herein can be dimensioned in awide variety of manners. Referring in particular to FIG. 3 , the depthof Schlemm's canal 22 is typically about less than 400 microns (μm).Accordingly, the stunt blade 34 is dimensioned so that the height of theblade 34 (referred to as H₄₁ in FIG. 4 ) is typically less than about400 μm. The snorkel shank 40 is dimensioned so that it has a length(referred to as L₄₁ in FIG. 4 ) typically in the range from about 100 μmto about 300 μm which is roughly the typical range of the thickness ofthe trabecular meshwork 21.

Of course, as the skilled artisan will appreciate, that with the stent30 implanted, the blade 34 may rest at any suitable position withinSchlemm's canal 22. For example, the blade 34 may be adjacent to a frontwall 90 of Schlemm's canal 22 (as shown in FIG. 3 ), or adjacent to aback wall 92 of Schlemm's canal 22, or at some intermediate locationtherebetween, as needed or desired. Also, the snorkel shank 40 mayextend into Schlemm's canal 22. The length of the snorkel shank 40and/or the dimensions of the blade 34 may be efficaciously adjusted toachieve the desired implant positioning.

The trabecular stenting device 30 (FIGS. 3-9 ) of the exemplaryembodiment may be manufactured or fabricated by a wide variety oftechniques. These include, without limitation, by molding,thermo-forming, or other micro-machining techniques, among othersuitable techniques.

The trabecular stenting device 30 preferably comprises a biocompatiblematerial such that inflammation arising due to irritation between theouter surface of the device 30 and the surrounding tissue is minimized.Biocompatible materials which may be used for the device 30 preferablyinclude, but are not limited to, titanium, titanium alloys, medicalgrade silicone, e.g., Silastic™, available from Dow Coming Corporationof Midland, Mich.; and polyurethane, e.g., Pellethane™, also availablefrom Dow Corning Corporation.

In other embodiments, the stent device 30 may comprise other types ofbiocompatible material, such as, by way of example, polyvinyl alcohol,polyvinyl pyrolidone, collagen, heparinized collagen,polytetrafluoroethylene, expanded polytetrafluoroethylene, fluorinatedpolymer, fluorinated elastomer, flexible fused silica, polyolefin,polyester, polysilicon, and/or a mixture of the aforementionedbiocompatible materials, and the like. In still other embodiments,composite biocompatible material may be used, wherein a surface materialmay be used in addition to one or more of the aforementioned materials.For example, such a surface material may include polytetrafluoroethylene(PTFE) (such as Teflon™), polyimide, hydrogel, heparin, therapeuticdrugs (such as beta-adrenergic antagonists and other anti-glaucomadrugs, or antibiotics), and the like.

In an exemplary embodiment of the trabecular meshwork surgery, thepatient is placed in the supine position, prepped, draped andanesthetized as necessary. In one embodiment, a small (less than about 1mm) incision, which may be self-sealing is made through the cornea 12.The corneal incision can be made in a number of ways, for example, byusing a micro-knife, among other tools.

An applicator or delivery apparatus is used to advance the glaucomastent 30 through the corneal incision and to the trabecular meshwork 21.Some embodiments of such a delivery apparatus are disclosed in U.S.application Ser. No. 10/101,548, filed Mar. 18, 2002, entitledAPPLICATOR AND METHODS FOR PLACING A TRABECULAR SHUNT FOR GLAUCOMATREATMENT, and U.S. Provisional Application No. 60/276,609, filed Mar.16, 2001, entitled APPLICATOR AND METHODS FOR PLACING A TRABECULAR SHUNTFOR GLAUCOMA TREATMENT, the entire contents of each one of which arehereby incorporated by reference herein. Some embodiments of a deliveryapparatus are also discussed in further detail later herein.Gonioscopic, microscopic, or endoscopic guidance may be used during thetrabecular meshwork surgery.

With the device 30 held by the delivery apparatus, the blade 34 of theself-trephining glaucoma stent device 30 is used to cut and/or displacethe material of the trabecular meshwork 21. The snorkel shank 40 mayalso facilitate in removal of this material during implantation. Thedelivery apparatus is withdrawn once the device 30 has been implanted inthe eye 10. As shown in FIG. 3 , once proper implantation has beenaccomplished the snorkel seat 38 rests on a top surface 94 of thetrabecular meshwork 21, the snorkel shank 40 extends through the cavity50 (created by the device 30) in the trabecular meshwork 21, and theblade extends inside Schlemm's canal 22.

Advantageously, the embodiments of the self-trephining stent device ofthe invention allow for a “one-step” procedure to make an incision inthe trabecular meshwork and to subsequently implant the stent in theproper orientation and alignment within the eye to allow outflow ofaqueous from the anterior chamber through the stent and into Schlemm'scanal to lower and/or balance the intraocular pressure (IOP). Desirably,this provides for a faster, safer, and less expensive surgicalprocedure.

Many complications can arise in trabecular meshwork surgeries, wherein aknife is first used to create an incision in the trabecular meshwork,followed by removal of the knife and subsequent installation of thestent. For instance, the knife may cause some bleeding which clouds upthe surgical site. This may require more effort and time to clean thesurgical site prior to placement of the stent. Moreover, this may causethe intraocular pressure (IOP) to rise. Thus, undesirably, such amultiple step procedure may demand crisis management which slows downthe surgery, makes it less safe, and more expensive.

FIG. 14 is a simplified partial view of an eye 10 illustrating theimplantation of a self-trephining glaucoma stent device 30 a havingfeatures and advantages in accordance with one embodiment. The stent 30a is generally similar to the stent 30 of FIGS. 3-9 except that itssnorkel 32 a comprises a longer shank 40 a which extends into Schlemm'scanal 22 and a lumen 42 a which bifurcates into two output channels 45a.

In the illustrated embodiment of FIG. 14 , the shank 40 a terminates atthe blade 34. Aqueous flows from the anterior chamber 20 into the lumen42 a through an inlet port 54 a (as generally indicated by arrow 58 a).Aqueous then flows through the output channels 45 a and out ofrespective outlet ports 56 a and into Schlemm's canal 22 (as generallyindicated by arrows 60 a). The outlet channels 45 a extend radiallyoutwards in generally opposed directions and the outlet ports 56 a areconfigured to face in the general direction of the stent longitudinalaxis 36 so that they open into Schlemm's canal 22 and are in properorientation to allow aqueous outflow into Schlemm's canal 22 forlowering and/or balancing the intraocular pressure (IOP). As indicatedabove, fiducial marks or indicia and/or predetermined shapes of thesnorkel seat 38 allow for proper orientation of the blade 34 and alsothe output channels 45 a and respective ports 56 a within Schlemm'scanal.

In the illustrated embodiment of FIG. 14 , two outflow channels 45 a areprovided. In another embodiment, only one outflow channel 45 a isprovided. In yet another embodiment, more than two outflow channels 45 aare provided. In modified embodiments, the lumen 42 a may extend all theway through to the blade 34 and provide an outlet port as discussedabove with reference to the embodiment of FIGS. 3-9 .

FIG. 15 is a simplified partial view of an eye 10 illustrating theimplantation of a self-trephining glaucoma stent device 30 b havingfeatures and advantages in accordance with one embodiment. The stent 30b is generally similar to the stent 30 of FIGS. 3-9 except that itssnorkel 32 b comprises a longer shank 40 b which extends into Schlemm'scanal 22 and a lumen 42 b which bifurcates into two output channels 45b.

In the illustrated embodiment of FIG. 15 , the shank 40 b extendsthrough the blade 34. Aqueous flows from the anterior chamber 20 intothe lumen 42 b through an inlet port 54 b (as generally indicated byarrow 58 b). Aqueous then flows through the output channels 45 b and outof respective outlet ports 56 b and into Schlemm's canal 22 (asgenerally indicated by arrows 60 b). The outlet channels 45 b extendradially outwards in generally opposed directions and the outlet ports56 b are configured to face in the general direction of the stentlongitudinal axis 36 so that they open into Schlemm's canal 22 and arein proper orientation to allow aqueous outflow into Schlemm's canal 22for lowering and/or balancing the intraocular pressure (IOP). Asindicated above, fiducial marks or indicia and/or predetermined shapesof the snorkel seat 38 allow for proper orientation of the blade 34 andalso the output channels 45 b and respective ports 56 b within Schlemm'scanal.

In the illustrated embodiment of FIG. 15 , two outflow channels 45 b areprovided. In another embodiment, only one outflow channel 45 b isprovided. In yet another embodiment, more than two outflow channels 45 bare provided. In modified embodiments, the lumen 42 b may extend all theway through to the blade 34 and provide an outlet port as discussedabove with reference to the embodiment of FIGS. 3-9 .

FIGS. 16-20 show different views of a self-trephining glaucoma stentdevice 30 c having features and advantages in accordance with oneembodiment. The stent 30 c is generally similar to the stent 30 of FIGS.3-9 except that it has a modified blade configuration. The stent 30 ccomprises a blade 34 c which is a generally curved elongated sheet- orplate-like structure with an upper curved surface 62 c and a lowercurved surface 64 c which defines a trough or open face channel 66 c.The perimeter of the blade 34 c is generally defined by a curvedproximal edge 68 c proximate to the snorkel 32, a curved distal edge 70c spaced from the proximal edge 68 c by a pair of generally straightlateral edges 72 c, 74 c which are generally parallel to one another andhave about the same length.

In the illustrated embodiment of FIGS. 16-20 , the blade 34 c comprisesa cutting tip 78 c. The cutting tip 78 c preferably includes cuttingedges formed on selected portions of the distal edge 70 c and adjacentportions of the lateral edges 72 c, 74 c for cutting through thetrabecular meshwork for placement of the snorkel 32. The cutting edgesare sharp edges of beveled or tapered surfaces as discussed above inreference to FIG. 9 . The embodiment of FIGS. 16-20 may be efficaciouslymodified to incorporate the snorkel configuration of the embodiments ofFIGS. 14 and 15 .

FIGS. 21-25 show different views of a self-trephining glaucoma stentdevice 30 d having features and advantages in accordance with oneembodiment. The stent 30 d is generally similar to the stent 30 of FIGS.3-9 except that it has a modified blade configuration. The stent 30 dcomprises a blade 34 d which is a generally curved elongated sheet- orplate-like structure with an upper curved surface 62 d and a lowercurved surface 64 d which defines a trough or open face channel 66 d.The perimeter of the blade 34 d is generally defined by a curvedproximal edge 68 d proximate to the snorkel 32, a pair of inwardlyconverging curved distal edges 70 d′, 70 d″ spaced from the proximaledge 68 d by a pair of generally straight respective lateral edges 72 d,74 d which are generally parallel to one another and have about the samelength. The distal edges 70 d′, 70 d″ intersect at a distal-most point76 d of the blade 34 d proximate a blade cutting tip 78 d.

In the illustrated embodiment of FIGS. 21-25 , the cutting tip 78 dpreferably includes cutting edges formed on the distal edges 70 d′, 70d″ and extending from the distal-most point 76 d of the blade 34 d. Inone embodiment, the cutting edges extend along only a portion ofrespective distal edges 70 d′, 70 d″. In another embodiment, the cuttingedges extend along substantially the entire length of respective distaledges 70 d′, 70 d″. In yet another embodiment, at least portions of thelateral edges 72 d, 74 d proximate to respective distal edges 70 d′, 70d″ have cutting edges. In a further embodiment, the tip 78 d proximateto the distal-most end 76 d is curved slightly inwards, as indicatedgenerally by the arrow 88 d in FIG. 21 and arrow 88 d (pointedperpendicular and into the plane of the paper) in FIG. 22 , relative tothe adjacent curvature of the blade 34 d.

In the embodiment of FIGS. 21-25 , the cutting edges are sharp edges ofbeveled or tapered surfaces as discussed above in reference to FIG. 9 .The embodiment of FIGS. 21-25 may be efficaciously modified toincorporate the snorkel configuration of the embodiments of FIGS. 14 and15 .

FIGS. 26-28 show different views of a self-trephining glaucoma stentdevice 30 e having features and advantages in accordance with oneembodiment. The stent device 30 e generally comprises a snorkel 32 emechanically connected to or in mechanical communication with a blade orcutting tip 34 e. The snorkel 32 e has a seat, head or cap portion 38 emechanically connected to or in mechanical communication with a shank 40e, as discussed above. The shank 40 e has a distal end or base 47 e. Thesnorkel 32 e further has a lumen 42 e which bifurcates into a pair ofoutlet channels 45 e, as discussed above in connection with FIGS. 14 and15 . Other lumen and inlet and outlet port configurations as taught orsuggested herein may also be efficaciously used, as needed or desired.

In the illustrated embodiment of FIGS. 26-28 , the blade 34 e extendsdownwardly and outwardly from the shank distal end 47 e. The blade 34 eis angled relative to a generally longitudinal axis 43 e of the snorkel32 e, as best seen in FIGS. 27 and 28 . The blade 34 e has a distal-mostpoint 76 e. The blade or cutting tip 34 e has a pair of side edges 70e′, 70 e″, including cutting edges, terminating at the distal-most point76 e, as best seen in FIG. 26 . In one embodiment, the cutting edges aresharp edges of beveled or tapered surfaces as discussed above inreference to FIG. 9 .

Referring to FIGS. 26-28 , in one embodiment, the blade 34 e includescutting edges formed on the edges 70 e′, 70 e″ and extending from thedistal-most point 76 e of the blade 34 d. In one embodiment, the cuttingedges extend along only a portion of respective distal edges 70 e′, 70e″. In another embodiment, the cutting edges extend along substantiallythe entire length of respective distal edges 70 e′, 70 e″. In yetanother embodiment, the blade or cutting tip 34 e comprises a bent tipof needle, for example, a 30 gauge needle.

In general, any of the blade configurations disclosed herein may be usedin conjunction with any of the snorkel configurations disclosed hereinor incorporated by reference herein to provide a self-trephiningglaucoma stent device for making an incision in the trabecular meshworkfor receiving the corresponding snorkel to provide a pathway for aqueousoutflow from the eye anterior chamber to Schlemm's canal, therebyeffectively lowering and/or balancing the intraocular pressure (IOP).The self-trephining ability of the device, advantageously, allows for a“one-step” procedure in which the incision and placement of the snorkelare accomplished by a single device and operation. In any of theembodiments, fiducial markings or indicia, and/or preselectedconfiguration of the snorkel seat, and/or positioning of the stentdevice in a preloaded applicator may be used for proper orientation andalignment of the device during implantation.

Delivery Apparatus

In many cases, a surgeon works from a temporal incision when performingcataract or goniometry surgery. FIG. 29 illustrates a temporal implantprocedure, wherein a delivery apparatus or “applicator” 100 having acurved tip 102 is used to deliver a stent 30 to a temporal side 27 ofthe eye 10. An incision 28 is made in the cornea 10, as discussed above.The apparatus 100 is then used to introduce the stent 30 through theincision 28 and implant it within the eye 10.

Still referring in particular to FIG. 29 , in one embodiment, asimilarly curved instrument would be used to make the incision throughthe trabecular meshwork 21. In other embodiments, a self-trephiningstent device 30 may be used to make this incision through the trabecularmeshwork 21, as discussed above. The temporal implantation procedureillustrated in FIG. 29 may be employed with the any of the various stentembodiments taught or suggested herein.

FIG. 30 illustrates one embodiment of an apparatus comprising anarticulating stent applicator or retrieval device 100 a. In thisembodiment, a proximal arm 106 is attached to a distal arm 108 at ajoint 112. This joint 112 is movable such that an angle formed betweenthe proximal arm 106 and the distal arm 108 can change. One or moreclaws 114 can extend from the distal arm 108, in the case of a stentretrieval device. Similarly, this articulation mechanism may be used forthe trabecular stent applicator, and thus the articulating applicator orretrieval device 100 a may be either an applicator for the trabecularstent, a retrieval device, or both, in various embodiments. Theembodiment of FIG. 30 may be employed with the any of the various stentembodiments taught or suggested herein.

FIG. 31 shows another illustrative method for placing any of the variousstent embodiments taught or suggested herein at the implant site withinthe eye 10. A delivery apparatus 100 b generally comprises a syringeportion 116 and a cannula portion 118. The distal section of the cannula118 has at least one irrigating hole 120 and a distal space 122 forholding the stent device 30. The proximal end 124 of the lumen of thedistal space 122 is sealed from the remaining lumen of the cannulaportion 118. The delivery apparatus of FIG. 30 may be employed with theany of the various stent embodiments taught or suggested herein.

In one aspect of the invention, a delivery apparatus (or “applicator”)is used for placing a trabecular stent through a trabecular meshwork ofan eye. Certain embodiments of such a delivery apparatus are disclosedin U.S. application Ser. No. 10/101,548, filed Mar. 18, 2002, entitledAPPLICATOR AND METHODS FOR PLACING A TRABECULAR SHUNT FOR GLAUCOMATREATMENT, and U.S. Provisional Application No. 60/276,609, filed Mar.16, 2001, entitled APPLICATOR AND METHODS FOR PLACING A TRABECULAR SHUNTFOR GLAUCOMA TREATMENT, the entire contents of each one of which arehereby incorporated by reference herein.

The stent has an inlet section and an outlet section. The deliveryapparatus includes a handpiece, an elongate tip, a holder and anactuator. The handpiece has a distal end and a proximal end. Theelongate tip is connected to the distal end of the handpiece. Theelongate tip has a distal portion and is configured to be placed througha corneal incision and into an anterior chamber of the eye. The holderis attached to the distal portion of the elongate tip. The holder isconfigured to hold and release the inlet section of the trabecularstent. The actuator is on the handpiece and actuates the holder torelease the inlet section of the trabecular stent from the holder. Whenthe trabecular stent is deployed from the delivery apparatus into theeye, the outlet section is positioned in substantially oppositedirections inside Schlemm's canal. In one embodiment, a deploymentmechanism within the delivery apparatus includes a push-pull typeplunger.

In some embodiments, the holder comprises a clamp. In some embodiments,the apparatus further comprises a spring within the handpiece that isconfigured to be loaded when the stent is being held by the holder, thespring being at least partially unloaded upon actuating the actuator,allowing for release of the stent from the holder.

In various embodiments, the clamp comprises a plurality of clawsconfigured to exert a clamping force onto the inlet section of thestent. The holder may also comprise a plurality of flanges.

In some embodiments, the distal portion of the elongate tip is made of aflexible material. This can be a flexible wire. The distal portion canhave a deflection range, preferably of about 45 degrees from the longaxis of the handpiece.

The delivery apparatus can further comprise an irrigation port in theelongate tip.

Some aspects include a method of placing a trabecular stent through atrabecular meshwork of an eye, the stent having an inlet section and anoutlet section, including advancing a delivery apparatus holding thetrabecular stent through an anterior chamber of the eye and into thetrabecular meshwork, placing part of the stent through the trabecularmeshwork and into a Schlemm's canal of the eye; and releasing the stentfrom the delivery apparatus.

In various embodiments, the method includes using a delivery apparatusthat comprises a handpiece having a distal end and a proximal end; anelongate tip connected to the distal end of the handpiece, the elongatetip having a distal portion and being configured to be placed through acorneal incision and into an anterior chamber of the eye; a holderattached to the distal portion of the elongate tip, the holderconfigured to hold and release the inlet section of the trabecularstent; and an actuator on the handpiece that actuates the holder torelease the inlet section of the trabecular stent from the holder.

In one aspect, the trabecular stent is removably attached to a deliveryapparatus (also known as “applicator”). When the trabecular stent isdeployed from the delivery apparatus into the eye, the outlet section ispositioned in substantially opposite directions inside Schlemm's canal.In one embodiment, a deployment mechanism within the delivery apparatusincludes a push-pull type plunger. In some embodiments, the deliveryapplicator may be a guidewire, an expandable basket, an inflatableballoon, or the like.

Other Embodiments

Screw/Barb Anchored Stent:

FIGS. 32 and 33 illustrate a glaucoma stent device 30 f having featuresand advantages in accordance with one embodiment. This embodiment of thetrabecular stent 30 f includes a barbed or threaded screw-like extensionor pin 126 with barbs 128 for anchoring. The barbed pin 126 extends froma distal or base portion 130 of the stent 30 f.

In use, the stent 30 f (FIG. 32 ) is advanced through the trabecularmeshwork 21 and across Schlemm's canal 22. The barbed (or threaded)extension 126 penetrates into the back wall 92 of Schlemm's canal 22 upto the shoulder or base 130 that then rests on the back wall 92 of thecanal 22. The combination of a shoulder 130 and a barbed pin 126 of aparticular length limits the penetration depth of the barbed pin 126 toa predetermined or preselected distance. In one embodiment, the lengthof the pin 126 is about 0.5 mm or less. Advantageously, this barbedconfiguration provides a secure anchoring of the stent 30 f. Asdiscussed above, correct orientation of the stent 30 f is ensured byappropriate fiducial marks, indicia or the like and by positioning ofthe stent in a preloaded applicator.

Referring to FIG. 32 , the aqueous flows from the anterior chamber 20,through the lumen 42 f, then out through two side-ports 56 f to bedirected in both directions along Schlemm's canal 22. Alternatively,flow could be directed in only one direction through a single side-port56 f. In other embodiments, more than two outlet ports 56 f, forexample, six to eight ports (like a pin wheel configuration), may beefficaciously used, as needed or desired.

Still referring to FIG. 32 , in one embodiment, the stent 30 f isinserted through a previously made incision in the trabecular meshwork21. In other embodiments, the stent 30 f may be combined with any of theblade configurations taught or suggested herein to provideself-trephining capability. In these cases, the incision through thetrabecular meshwork 21 is made by the self-trephining stent device whichhas a blade at its base or proximate to the base.

Deeply Threaded Stent:

FIG. 34 illustrates a glaucoma stent device 30 g having features andadvantages in accordance with one embodiment. The stent 30 g has a heador seat 38 g and a shank or main body portion 40 g with a base or distalend 132. This embodiment of the trabecular stent 30 g includes a deepthread 134 (with threads 136) on the main body 40 g of the stent 30 gbelow the head 38 g. The threads may or may not extend all the way tothe base 132.

In use, the stent 30 g (FIG. 34 ) is advanced through the meshwork 21through a rotating motion, as with a conventional screw. Advantageously,the deep threads 136 provide retention and stabilization of the stent 30g in the trabecular meshwork 21.

Referring to FIG. 34 , the aqueous flows from the anterior chamber 20,through the lumen 42 g, then out through two side-ports 56 g to bedirected in both directions along Schlemm's canal 22. Alternatively,flow could be directed in only one direction through a single side-port56 g. In other embodiments, more than two outlet ports 56 g may beefficaciously used, as needed or desired.

One suitable applicator or delivery apparatus for this stent 30 g (FIG.34 ) includes a preset rotation, for example, via a wound torsion springor the like. The rotation is initiated by a release trigger on theapplicator. A final twist of the applicator by the surgeon andobservation of suitable fiducial marks, indicia or the like ensureproper alignment of the side ports 56 g with Schlemm's canal 22.

Referring to FIG. 34 , in one embodiment, the stent 30 g is insertedthrough a previously made incision in the trabecular meshwork 21. Inother embodiments, the stent 30 g may be combined with any of the bladeconfigurations taught or suggested herein to provide self-trephiningcapability. In these cases, the incision through the trabecular meshwork21 is made by the self-trephining stent device which has a blade at itsbase or proximate to the base.

Rivet Style Stent:

FIG. 35 illustrates a glaucoma stent device 30 h having features andadvantages in accordance with one embodiment. The stent has a base ordistal end 138. This embodiment of the trabecular stent 30 h has a pairof flexible ribs 140. In the unused state, the ribs are initiallygenerally straight (that is, extend in the general direction of arrow142).

Referring to FIG. 35 , upon insertion of the stent 30 h through thetrabecular meshwork 21, the ends 144 of respective ribs 140 of the stent30 h come to rest on the back wall 92 of Schlemm's canal 22. Furtheradvancement of the stent 30 h causes the ribs 140 to deform to the bentshape as shown in the drawing of FIG. 35 . The ribs 140 are designed tofirst buckle near the base 138 of the stent 30 h. Then the bucklingpoint moves up the ribs 140 as the shank part 40 h of the stent 30 h isfurther advanced through the trabecular meshwork 21.

The lumen 42 h (FIG. 35 ) in the stent 30 h is a simple straight hole.The aqueous flows from the anterior chamber 20, through the lumen 42 h,then out around the ribs 140 to the collector channels further alongSchlemm's canal 22 in either direction.

Referring to FIG. 35 , in one embodiment, the stent 30 h is insertedthrough a previously made incision in the trabecular meshwork 21. Inother embodiments, the stent 30 h may be combined with any of the bladeconfigurations taught or suggested herein to provide self-trephiningcapability. In these cases, the incision through the trabecular meshwork21 is made by the self-trephining stent device which has a blade at itsbase or proximate to the base.

Grommet Style Stent:

FIG. 36A illustrates a glaucoma stent device 30 i having features andadvantages in accordance with one embodiment. This embodiment of thetrabecular stent 30 i includes a head or seat 38 i, a tapered baseportion 146 and an intermediate narrower waist portion or shank 40 i.

In use, the stent 30 i (FIG. 36A) is advanced through the trabecularmeshwork 21 and the base 146 is pushed into Schlemm's canal 22. Thestent 30 i is pushed slightly further, if necessary, until the meshwork21 stretched by the tapered base 146 relaxes back and then contracts toengage the smaller diameter portion waist 40 i of the stent 30 i.Advantageously, the combination of the larger diameter head or seat 38 iand base 146 of the stent 30 i constrains undesirable stent movement. Asdiscussed above, correct orientation of the stent 30 i is ensured byappropriate fiducial marks, indicia or the like and by positioning ofthe stent in a preloaded applicator.

Referring to FIG. 36A, the aqueous flows from the anterior chamber 20,through the lumen 42 i, then out through two side-ports 56 i to bedirected in both directions along Schlemm's canal 22. Alternatively,flow could be directed in only one direction through a single side-port56 i. In other embodiments, more than two outlet ports 56 i may beefficaciously used, as needed or desired.

Still referring to FIG. 36A, in one embodiment, the stent 30 i isinserted through a previously made incision in the trabecular meshwork21. In other embodiments, the stent 30 i may be combined with any of theblade configurations taught or suggested herein to provideself-trephining capability. In these cases, the incision through thetrabecular meshwork 21 is made by the self-trephining stent device whichhas a blade at its base or proximate to the base.

FIG. 36B and FIG. 36C illustrate another embodiment of a trabecularstent 30 i′. FIG. 36B shows the glaucoma stent device 30 i′ from theside while FIG. 36C shows the glaucoma stent device 30 i′ from abase-biased three-quarters view. The glaucoma stent device 30 i′includes a head or seat 38 i′ with a head or seat depth 38 d, a waistportion or shank 40 i′ with a waist portion or shank external diameter40 n and a waist portion or shank depth 40 m, a lumen 42 i′, a side-port56 i′, a tapered base 146′, an angle α, and an angle θ.

In operation, the glaucoma stent device 30 i′ of FIG. 36B and 36C isadvanced through the trabecular meshwork 21 of FIG. 2 and the taperedbase 146′ is pushed into Schlemm's canal 22 of FIG. 2 . The glaucomastent device 30 i′ is pushed slightly further, if necessary, until themeshwork 21 of FIG. 2 stretched by the tapered base 146′ relaxes backand then contracts to engage the smaller diameter portion waist portionor shank 40 i′ of the glaucoma stent device 30 i′. Advantageously, thecombination of the larger diameter head or seat 38 i′ and tapered base146′ of the glaucoma stent device 30 i′ increases the implantationsuccess and constrains undesirable stent movement. In some embodiments,a hole is made in the trabecular meshwork 21 of FIG. 2 with a device(such as, but not limited to a knife, trephine, punch, drill, scalpel,trocar, or blade) before the glaucoma stent device 30 i′ is introducedinto the anterior chamber of the eye. In other embodiments, a hole ismade in the trabecular meshwork 21 of FIG. 2 using the delivery deviceused to deliver the glaucoma stent device 30 i′ to the trabecularmeshwork 21 of FIG. 21 .

Generally, the tapered base 146′ is attached to the waist portion orshank 40 i′ which is attached to the head or seat 38 i′ to form theglaucoma stent device 30 i′ illustrated in FIGS. 36B and 36C. A lumen 42i′ runs from the top of the head or seat 38 i′ to the bottom of thetapered base 146′ to provide a fluid channel from the anterior chamberto the internal lumen of Schlemm's canal.

In some embodiments, there are four side-ports 56 i′ intersecting thelumen 42 i′ in the region of the tapered base 146′. In some embodiments,the at least one side-port 56 i′ intersects perpendicular to the lumen42 i′ (as shown in FIGS. 36B and 36C). In some embodiments, theside-ports 56 i′ intersect each other in a perpendicular fashion (asshown in FIGS. 36B and 36C). In some embodiments, there is only oneside-port 56 i′. In some embodiments, there are two side-ports 56 i′,three side-ports 56 i′, four side-ports 56 i′, five side-ports 56 i′, orsix side-ports 56 i′. The side-ports 56 i′ can be generally parallel tothe axis of Schlemm's canal or simply positioned to be aligned in ornear Schlemm's canal. The side-ports 56 i′ and provide for additionalflow of aqueous from the anterior chamber to the lumen of Schlemm'scanal. Side-ports 56 i′ can be particularly useful if the terminal endof the lumen 42 i′ residing in Schlemm's canal either becomes plugged orabuts the wall of Schlemm's canal and has concomitantly lower ordecreased or even arrested fluid flow.

In some embodiments, the head or seat 38 i′of the glaucoma stent device30 i′ has a diameter in the range of about 100-3000 μm, about 150-3750μm, about 200-3500 μm, about 200-3250 μm, about 250-3000 μm, about300-2750 μm, about 350-2500 μm, about 375-2250 μm, about 400-2000 μm,about 450-1750 μm, about 500-1500 μm, about 550-1250 μm, about 600-1000μm, and about 650-800 μm or any other diameter which fits within the eyeand serves to anchor the glaucoma stent device 30 i′ appropriately.

In some embodiments, the head or seat depth 38 d of the glaucoma stentdevice 30 i′ is in the range of about 50-1000 μm, about 60-900 μm, about70-800 μm, about 80-700 μm, about 90-600 μm, about 100-500 μm, about110-400 μm, and about 120-300 including about 130-200 μm or any otherdepth which allows the glaucoma stent device 30 i′ to seat in the eyeand maintain structural integrity and/or alignment of side-ports 56 i′to Schlemm's canal.

In some embodiments, the waist portion or shank depth 40 m of theglaucoma stent device 30 i′ is approximately equal to the thickness ofthe trabecular meshwork 21 of FIG. 2 , including the range of about100-500 μm, about 110-450 μm, about 120-400 μm, about 130-350 μm, about140-300 μm, about 150-250 μm, and about 160-200 μm.

In some embodiments, the waist portion or shank external diameter 40 nof the glaucoma stent device 30 i′ is in the range of about 100-1500 μm,about 150-1400 μm, about 160-1300 μm, about 170-1200 μm, about 180-1100μm, about 190-1000 μm, about 200-900 μm, about 210-800 μm, about 220-700μm, about 230-600 μm, about 240-500 μm, about 250-400, and about 260-300μm.

In some embodiments, angle α formed by the attachment of the head orseat 38 i′ to the waist portion or shank 40 i′ is in the range of about5-45°, about 7.5-40°, about 10-35°, about 12.5-30°, about 15-25°, andabout 17.5-20°. Generally, the lower the angle α, the more of the heador seat 38 i′portion of the glaucoma stent device 30 i′ can be incontact with the trabecular meshwork 21 of FIG. 2 .

In some embodiments, the angle θ of the tapered base 146′ is in therange of about 45-80°, about 47.5-77.5°, about 50-75°, about 52.5-72.5°,about 55-70°, about 57.5-67.5°, and about 60-65° or any other angleappropriate for fitting inside Schlemm's canal and helping in anchoringthe glaucoma stent device 30 i′ in the eye.

In some embodiments, the tapered base 146′ is approximately as deep asis Schlemm's canal. In some embodiments, the periphery of the taperedbase 146′ is approximately equal to the periphery of the cross sectionof Schlemm's canal. In some embodiments, the tapered base 146′ isflattened (as shown in FIG. 36B. In some embodiments, the tapered base146′ is not flattened and can extend into the tissue of the wall ofSchlemm's canal to anchor the glaucoma stent device 30 i′.

FIGS. 36D, 36E, and 36F illustrate another embodiment of a glaucomastent device 30 i′. The glaucoma stent device 30 i′ illustrated in FIGS.36D-36F can have approximately the same structures as the glaucoma stentdevice 30 i′ illustrated in FIG. 36B and 36C described immediatelyabove, including but not limited to a tapered base 146′, a waist portionor shank 40 i′, a head or seat 38 i′, a lumen 42 i′, and at least oneside-port 56 i′. In addition to the aforementioned features, in someembodiments, the glaucoma stent device 30 i′ of FIGS. 36D-36F caninclude at least one head or seat side-port 57 i′.

In some embodiments, the head or seat side-port 57 i′ can extend throughthe head or seat 38 i′ (e.g., parallel to the planar surface of the heador seat 38 i′). In some embodiments, the head or seat side-port 57 i′can be disposed parallel to the at least one side-port 56 i′ in thetapered base 146′.

In some embodiments, there are four head or seat side-ports 57 i′intersecting the lumen 42 i′ in the region of the head or seat 38 i′. Insome embodiments, the at least one head or seat side-port 57 i′intersects perpendicular to the lumen 42 i′ (as shown in FIG. 36D). Insome embodiments, the head or seat side-ports 57 i′ intersect each otherin a perpendicular fashion (as shown in FIG. 36E). In some embodiments,there is only one head or seat side-port 57 i′. In some embodiments,there are two head or seat side-ports 57 i′, three head or seatside-ports 57 i′, four head or seat side-ports 57 i′, five head or seatside-ports 57 i′, or six head or seat side-ports 57 i′. The head or seatside-ports 57 i′ can be generally parallel to the axis of Schlemm'scanal. In some embodiments, when in an implanted location, the head orseat side-ports 57 i′ can be located in the anterior chamber of the eye.The head or seat side-ports 57 i′ can provide for additional flow ofaqueous from the anterior chamber to the lumen of Schlemm's canal.

The glaucoma stent device 30 i′ illustrated in FIGS. 36D, 36E, and 36Fcan be particularly useful in closed angle patients. Additionally, thisglaucoma stent device 30 i′ can be inserted into the eye in combinationwith an iridotomy to create an improved outflow pathway in theaforementioned closed angle cases.

FIGS. 36G, 36H, and 36I illustrate another embodiment of a glaucomastent device 30 i′. The glaucoma stent device 30 i′ illustrated in FIGS.36G-36I can have approximately the same structures as the glaucoma stentdevice 30 i′ illustrated in FIGS. 36D, 36E, and 36F describedimmediately above, including but not limited to a tapered base 146′, awaist portion or shank 40 i′, a head or seat 38 i′, a lumen 42 i′, andat least one side-port 56 i′. In addition to the aforementionedfeatures, in some embodiments, the glaucoma stent device 30 i′ of FIGS.36G-36I can includes at least one head or seat half-cylinder side-port57 j′.

In some embodiments, the head or seat half-cylinder side-port 57 j′ canextend through the head or seat 38 i′ (e.g., parallel to the planarsurface of the head or seat 38 i′). In some embodiments, the head orseat half-cylinder side-port 57 j′ can be disposed parallel to the atleast one side-port 56 i′ in the tapered base 146′.

In some embodiments, there are four head or seat half-cylinderside-ports 57 j′ intersecting the lumen 42 i′ in the region of the heador seat 38 i′. In some embodiments, the at least one head or seathalf-cylinder side-port 57 j′ intersects perpendicular to the lumen 42i′ (as shown in FIG. 36G). In some embodiments, the head or seathalf-cylinder side-ports 57 j′ intersect each other in a perpendicularfashion (as shown in FIG. 36H). In some embodiments, there is only onehead or seat half-cylinder side-port 57 j′. In some embodiments, thereare two head or seat half-cylinder side-ports 57 j′, three head or seathalf-cylinder side-ports 57 j′, four head or seat half-cylinderside-ports 57 j′, five head or seat half-cylinder side-ports 57 j′, orsix head or seat half-cylinder side-ports 57 j′. The head or seathalf-cylinder side-ports 57 j′ can be generally parallel to the axis ofSchlemm's canal. In some embodiments, when in an implanted location, thehead or seat half-cylinder side-ports 57 j′ can be located in theanterior chamber of the eye. The head or seat half-cylinder side-ports57 j′ can provide for additional flow of aqueous from the anteriorchamber to the lumen of Schlemm's canal. The glaucoma stent device 30 i′illustrated in FIGS. 36G, 36H, and 36I can be particularly useful inclosed angle patients. Additionally, this glaucoma stent device 30 i′can be inserted into the eye in combination with an iridotomy to createan improved outflow pathway in the aforementioned closed angle cases.

FIGS. 36J and 36K illustrate another embodiment of a glaucoma stentdevice 30 i′. The glaucoma stent device 30 i′ illustrated in FIGS. 36Jand 36K can have approximately the same structures as the glaucoma stentdevice 30 i′ illustrated in FIGS. 36D, 36E, and 36F described above,including but not limited to a tapered base 146′, a waist portion orshank 40 i′, a head or seat 38 i′, a lumen 42 i′, and at least oneside-port 56 i′. In addition to the aforementioned features, in someembodiments, the glaucoma stent device 30 i′ of FIGS. 36J and 36K caninclude a head or seat shank 40 k′, a head or seat button 38 k′, a heador seat button dome 38 n, and at least one head or seat shank side-port57 k′.

In some embodiments, the head or seat shank 40 k′ can extend from theback of the head or seat 38 i′. In some embodiments, the head or seatshank 40 k′ can have a diameter less than the diameter of the head orseat 38 i′. In some embodiments, the diameter of the head or seat shank40 k′ can be in the range of about 20-100% of the diameter of the heador seat 38 i′, about 30-90% of the diameter of the head or seat 38 i′,about 40-80% of the diameter of the head or seat 38 i′ about 50-70% ofthe diameter of the head or seat 38 i′, and about 60% of the diameter ofthe head or seat 38 i′.

In some embodiments, the head or seat shank 40 k′ has a thickness in therange of about 100-500 μm, about 110-450 μm, about 120-400 μm, about130-350 μm, about 140-300 μm, about 150-250 μm, and about 160-200 μm.

In some embodiments, the head or seat button 38 k′ can extend from theback of the head or seat shank 40 k′. In some embodiments, the head orseat button 38 k′ can have a head or seat button dome 38 n. In otherembodiments, the head or seat button 38 k′ is flat. In some embodiments,the head or seat button 38 k′ can have a diameter the same as thediameter of the head or seat 38 i′. In some embodiments, the head orseat button 38 k′ can have a diameter that is greater than the diameterof the head or seat 38 i′. In some embodiments, the head or seat button38 k′ can have a diameter that is less than the diameter of the head orseat 38 i′. In some embodiments, the diameter of the head or seat button38 k′ can be in the range of about 50-150% of the diameter of the heador seat 38 i′, about 60-140% of the diameter of the head or seat 38 i′,about 70-130% of the diameter of the head or seat 38 i′, about 80-120%of the diameter of the head or seat 38 i′, about 90-110% of the diameterof the head or seat 38 i′, and about 100% of the diameter of the head orseat 38 i′.

In some embodiments, the head or seat button 38 k′ has a thickness inthe range of about 100-500 μm, about 110-450 μm, about 120-400 μm, about130-350 μm, about 140-300 μm, about 150-250 μm, and about 160-200 μm.

In some embodiments, the head or seat shank side-port 57 k′ can extendthrough the head or seat shank 40 k′ (e.g., parallel to the planarsurface of the head or seat 38 i′). In some embodiments, the head orseat shank side-port 57 k′ can be disposed parallel to the at least oneside-port 56 i′ in the tapered base 146′.

In some embodiments, there are four head or seat shank side-ports 57 k′intersecting the lumen 42 i′ in the region of the head or seat shank 40k′. In some embodiments, the at least one head or seat shank side-port57 k′ intersects perpendicular to the lumen 42 i′ (as shown in FIG.36J). In some embodiments, the head or seat shank side-ports 57 k′intersect each other in a perpendicular fashion (as shown in FIGS. 36Jand 36K). In some embodiments, there is only one head or seat shankside-port 57 k′. In some embodiments, there are two head or seat shankside-ports 57 k′, three head or seat shank side-ports 57 k′, four heador seat shank side-ports 57 k′, five head or seat shank side-ports 57k′, or six head or seat shank side-ports 57 k′. The head or seat shankside-ports 57 k′ can be generally parallel to the axis of Schlemm'scanal. In some embodiments, when in an implanted location, the head orseat shank side-port 57 k′ can be located in the anterior chamber of theeye. The head or seat shank side-ports 57 k′ can provide for additionalflow of aqueous from the anterior chamber to the lumen of Schlemm'scanal. The glaucoma stent device 30 i′ illustrated in FIGS. 36J and 36Kcan be particularly useful in closed angle patients. Additionally, thisglaucoma stent device 30 i′ can be inserted into the eye in combinationwith an iridotomy to create an improved outflow pathway in theaforementioned closed angle cases.

In some embodiments, one or more of the glaucoma stent devices discussedabove may be delivered into the eye with a delivery device such asdisclosed in the attached Appendix A which is a part of the presentspecification. One or more glaucoma stents may be preloaded onto thedelivery device to form a glaucoma stent/delivery device system.

Biointeractive Stent:

FIG. 37 illustrates a glaucoma stent device 30 j having features andadvantages in accordance with one embodiment. This embodiment of thetrabecular stent 30 j utilizes a region of biointeractive material 148that provides a site for the trabecular meshwork 21 to firmly grip thestent 30 j by ingrowth of the tissue into the biointeractive material148. As shown in FIG. 37 , preferably the biointeractive layer 148 isapplied to those surfaces of the stent 30 j which would abut against orcome in contact with the trabecular meshwork 21.

In one embodiment, the biointeractive layer 148 (FIG. 37 ) may be aregion of enhanced porosity with a growth promoting chemical. In oneembodiment, a type of bio-glue 150 that dissolves over time is used tohold the stent secure during the time between insertion and sufficientingrowth for stabilization. As discussed above, correct orientation ofthe stent 30 j is ensured by appropriate fiducial marks, indicia or thelike and by positioning of the stent in a preloaded applicator.

Referring to FIG. 37 , the aqueous flows from the anterior chamber 20,through the lumen 42 j, then out through two side-ports 56 j to bedirected in both directions along Schlemm's canal 22. Alternatively,flow could be directed in only one direction through a single side-port56 j. In other embodiments, more than two outlet ports 56 j may beefficaciously used, as needed or desired.

Still referring to FIG. 37 , in one embodiment, the stent 30 j isinserted through a previously made incision in the trabecular meshwork21. In other embodiments, the stent 30 j may be combined with any of theblade configurations taught or suggested herein to provideself-trephining capability. In these cases, the incision through thetrabecular meshwork 21 is made by the self-trephining stent device whichhas a blade at its base or proximate to the base.

Glued or Welded Stent:

FIG. 38 illustrates a glaucoma stent device 30 k having features andadvantages in accordance with one embodiment. This embodiment of thetrabecular stent 30 k is secured in place by using a permanent(non-dissolving) bio-glue 152 or a “welding” process (e.g. heat) to forma weld 152. The stent 30 k has a head or seat 38 k and a lower surface46 k.

The stent 30 k is advanced through the trabecular meshwork 21 until thehead or seat 38 k comes to rest on the trabecular meshwork 21, that is,the head lower surface 46 k abuts against the trabecular meshwork 21,and the glue or weld 152 is applied or formed therebetween, as shown inFIG. 38 . As discussed above, correct orientation of the stent 30 k isensured by appropriate fiducial marks, indicia or the like and bypositioning of the stent in a preloaded applicator.

Referring to FIG. 38 , the aqueous flows from the anterior chamber 20,through the lumen 42 k, then out through two side-ports 56 k to bedirected in both directions along Schlemm's canal 22. Alternatively,flow could be directed in only one direction through a single side-port56 k. In other embodiments, more than two outlet ports 56 k may beefficaciously used, as needed or desired.

Still referring to FIG. 38 , in one embodiment, the stent 30 k isinserted through a previously made incision in the trabecular meshwork21. In other embodiments, the stent 30 k may be combined with any of theblade configurations taught or suggested herein to provideself-trephining capability. In these cases, the incision through thetrabecular meshwork 21 is made by the self-trephining stent device whichhas a blade at its base or proximate to the base.

Hydrophilic Latching Stent:

FIG. 39 illustrates a glaucoma stent device 30 m having features andadvantages in accordance with one embodiment. This embodiment of thetrabecular stent 30 m is fabricated from a hydrophilic material thatexpands with absorption of water. Desirably, this would enable thedevice 30 m to be inserted through a smaller incision in the trabecularmeshwork 21. The subsequent expansion (illustrated by the smaller arrows154) of the stent 30 m would advantageously enable it to latch in placein the trabecular meshwork 21. As discussed above, correct orientationof the stent 30 m is ensured by appropriate fiducial marks, indicia orthe like and by positioning of the stent in a preloaded applicator.

Referring to FIG. 39 , the aqueous flows from the anterior chamber 20,through the lumen 42 m, then out through two side-ports 56 m to bedirected in both directions along Schlemm's canal 22. Alternatively,flow could be directed in only one direction through a single side-port56 m. In other embodiments, more than two outlet ports 56 m may beefficaciously used, as needed or desired.

Still referring to FIG. 39 , in one embodiment, the stent 30 m isinserted through a previously made incision in the trabecular meshwork21. In other embodiments, the stent 30 m may be combined with any of theblade configurations taught or suggested herein to provideself-trephining capability. In these cases, the incision through thetrabecular meshwork 21 is made by the self-trephining stent device whichhas a blade at its base or proximate to the base.

Photodynamic Stent:

FIG. 40 illustrates a glaucoma stent device 30 n having features andadvantages in accordance with one embodiment. This embodiment of thetrabecular stent 30 n is fabricated from a photodynamic material thatexpands on exposure to light.

It is commonly known that there is a diurnal variation in the aqueoushumor production by the eye—it is higher during the day than it is atnight. The lumen 42 n of the stent 30 n responds to light entering thecornea during the day by expanding and allowing higher flow of aqueousthrough the lumen 42 n and into Schlemm's canal 22. This expansion isgenerally indicated by the smaller arrows 156 (FIG. 40 ) which show thelumen 42 n (and ports) expanding or opening in response to lightstimulus. (The light or radiation energy E is generally given by E=hν,where h is Planck's constant and νis the frequency.) At night, indarkness, the lumen diameter decreases and reduces the flow allowedthrough the lumen 42 n. In one embodiment, an excitation wavelength thatis different from that commonly encountered is provided on an as-neededbasis to provide higher flow of aqueous to Schlemm's canal 22.

This photodynamic implementation is shown in FIG. 40 for theself-latching style of stent 30 n, but can be efficaciously used withany of the other stent embodiments, as needed or desired. As discussedabove, correct orientation of the stent 30 n is ensured by appropriatefiducial marks, indicia or the like and by positioning of the stent in apreloaded applicator.

Referring to FIG. 40 , the aqueous flows from the anterior chamber 20,through the lumen 42 n, then out through two side-ports 56 n to bedirected in both directions along Schlemm's canal 22. Alternatively,flow could be directed in only one direction through a single side-port56 n. In other embodiments, more than two outlet ports 56 n may beefficaciously used, as needed or desired.

Still referring to FIG. 40 , in one embodiment, the stent 30 n isinserted through a previously made incision in the trabecular meshwork21. In other embodiments, the stent 30 n may be combined with any of theblade configurations taught or suggested herein to provideself-trephining capability. In these cases, the incision through thetrabecular meshwork 21 is made by the self-trephining stent device whichhas a blade at its base or proximate to the base.

Collector Channel Alignment Stent:

FIG. 41 illustrates a glaucoma stent device 30 p having features andadvantages in accordance with one embodiment. This figure depicts anembodiment of a stent 30 p that directs aqueous from the anteriorchamber 20 directly into a collector channel 29 which empties intoaqueous veins. The stent 30 p has a base or distal end 160.

In the illustrated embodiment of FIG. 41 , a removable alignment pin 158is utilized to align the stent lumen 42 p with the collector channel 29.In use, the pin 158 extends through the stent lumen 42 p and protrudesthrough the base 160 and extends into the collector channel 29 to centerand/or align the stent 30 p over the collector channel 29. The stent 30p is then pressed firmly against the back wall 92 of Schlemm's canal 22.A permanent bio-glue 162 is used between the stent base and the backwall 92 of Schlemm's canal 22 to seat and securely hold the stent 30 pin place. Once positioned, the pin 158 is withdrawn from the lumen 42 pto allow the aqueous to flow directly from the anterior chamber 20 intothe collector duct 29. The collector ducts are nominally 20 to 100micrometers (μm) in diameter and are visualized with a suitablemicroscopy method (such as ultrasound biomicroscopy (UBM)) or laserimaging to provide guidance for placement of the stent 30 p.

Referring to FIG. 41 , in one embodiment, the stent 30 p is insertedthrough a previously made incision in the trabecular meshwork 21. Inother embodiments, the stent 30 p may be combined with any of the bladeconfigurations taught or suggested herein to provide self-trephiningcapability. In these cases, the incision through the trabecular meshwork21 is made by the self-trephining stent device which has a blade at itsbase or proximate to the base.

Barbed Stent (Anterior Chamber to Collector Channel):

FIG. 42 illustrates a glaucoma stent device 30 q having features andadvantages in accordance with one embodiment. This figure depicts anembodiment of a stent 30 q that directs aqueous from the anteriorchamber 20 directly into a collector channel 29 which empties intoaqueous veins. The stent 30 q has a base or distal end 166 and thechannel 29 has wall(s) 164.

In the illustrated embodiment of FIG. 42 , a barbed, small-diameterextension or pin 168 on the stent base 166 is guided into the collectorchannel 29 and anchors on the wall(s) 164 of the channel 29. The pin 168has barbs 170 which advantageously provide anchoring of the stent 30 q.The collector ducts 29 are nominally 20 to 100 micrometers (μm) indiameter and are visualized with a suitable microscopy method (such asultrasound biomicroscopy (UBM)) or laser imaging to provide guidance forplacement of the stent.

Referring to FIG. 42 , in one embodiment, the stent 30 q is insertedthrough a previously made incision in the trabecular meshwork 21. Inother embodiments, the stent 30 q may be combined with any of the bladeconfigurations taught or suggested herein to provide self-trephiningcapability. In these cases, the incision through the trabecular meshwork21 is made by the self-trephining stent device which has a blade at itsbase or proximate to the base.

Valved Tube Stent (Anterior Chamber to Choroid):

FIG. 43 illustrates a valved tube stent device 30 r having features andadvantages in accordance with one embodiment. This is an embodiment of astent 30 r that provides a channel for flow between the anterior chamber20 and the highly vascular choroid 17. Clinically, the choroid 17 can beat pressures lower than those desired for the eye 10. Therefore, thisstent 30 r includes a valve with an opening pressure equal to thedesired pressure difference between the choroid 17 and the anteriorchamber 10 or a constriction that provide the desired pressure drop.

Osmotic Membrane (Anterior Chamber to Choroid):

FIG. 44 illustrates an osmotic membrane device 30 s having features andadvantages in accordance with one embodiment. This embodiment provides achannel for flow between the anterior chamber 20 and the highly vascularchoroid 17. The osmotic membrane 30 s is used to replace a portion ofthe endothelial layer of the choroid 17. Since the choroid 17 is highlyvascular with blood vessels, the concentration of water on the choroidside is lower than in the anterior chamber 20 of the eye 10. Therefore,the osmotic gradient drives water from the anterior chamber 20 into thechoroid 17.

Clinically, the choroid 17 (FIG. 44 ) can be at pressures lower thanthose desired for the eye 10. Therefore, desirably, both osmoticpressure and the physical pressure gradient are in favor of flow intothe choroid 17. Flow control is provided by proper sizing of the area ofthe membrane,—the larger the membrane area is the larger the flow ratewill be. This advantageously enables tailoring to tune the flow to thedesired physiological rates.

Ab Externo Insertion of Stent via Small Puncture:

FIG. 45 illustrates the implantation of a stent 30 t using an ab externoprocedure having features and advantages in accordance with oneembodiment. In the ab externo procedure of FIG. 45 , the stent 30 t isinserted into Schlemm's canal 21 with the aid of an applicator ordelivery apparatus 100 c that creates a small puncture into the eye 10from outside.

Referring to FIG. 45 , the stent 30 t is housed in the applicator 100 c,and pushed out of the applicator 100 c once the applicator tip is inposition within the trabecular meshwork 21. Since the tissue surroundingthe trabecular meshwork 21 is optically opaque, an imaging technique,such as ultrasound biomicroscopy (UBM) or a laser imaging technique, isutilized. The imaging provides guidance for the insertion of theapplicator tip and the deployment of the stent 30 t. This technique canbe used with a large variety of stent embodiments with slightmodifications since the trabecular meshwork 21 is punctured from thescleral side rather than the anterior chamber side in the ab externoinsertion.

FIG. 46 a glaucoma stent device 30 u having features and advantages inaccordance with a modified embodiment. This grommet-style stent 30 u forab externo insertion is a modification of the embodiment of FIG. 36A. Inthe embodiment of FIG. 46 , the upper part or head 38 u is tapered whilethe lower part or base 172 is flat, as opposed to the embodiment of FIG.36A. The stent 30 u is inserted from the outside of the eye 10 through apuncture in the sclera. Many of the other embodiments of stents taughtor suggested herein can be modified for similar implantation.

This ultra-microscopic device 30 u (FIG. 46 ) can be used with (1) atargeting Lasik-type laser, or with (2) contact on eyes or with (3)combined ultrasound microscope or (4) other device insertor handpiece.

Targeted Drug Delivery to the Trabecular Meshwork:

FIG. 47 illustrates a targeted drug delivery implant 30 v havingfeatures and advantages in accordance with one embodiment. This drawingis a depiction of a targeted drug delivery concept. The slow releaseimplant 30 v is implanted within the trabecular meshwork 21.

A drug that is designed to target the trabecular meshwork 21 to increaseits porosity, or improve the active transport across the endotheliallayer of Schlemm's canal 22 can be stored in this small implant 30 v(FIG. 47 ). Advantageously, slow release of the drug promotes thedesired physiology at minimal dosage levels since the drug is releasedinto the very structure that it is designed to modify.

While the components and techniques of the invention have been describedwith a certain degree of particularity, it is manifest that many changesmay be made in the specific designs, constructions and methodologyherein above described without departing from the spirit and scope ofthis disclosure. It should be understood that the invention is notlimited to the embodiments set forth herein for purposes ofexemplification, but is to be defined only by a fair reading of theappended claims, including the full range of equivalency to which eachelement thereof is entitled.

What is claimed is:
 1. A system for treating an ocular disorder in apatient, the system comprising: a delivery device, said delivery devicecomprising a handpiece and an elongate delivery member; and a pluralityof glaucoma stents, each of the plurality of glaucoma stents comprising:a head portion comprising an inlet port; a base portion, the baseportion comprising at least one port and a tapered portion; a waistportion attached to the head portion at a first end and to the baseportion at a second end, the waist portion having an external diameterless than that of both an external diameter of a largest part of thebase portion and an external diameter of a largest part of the headportion; and a lumen at least partially passing through the headportion, base portion, and the waist portion, the lumen in communicationwith the at least one port, wherein the external diameter of the largestpart of the head portion is greater than the external diameter of thelargest part of the base portion.
 2. The system of claim 1, wherein theexternal diameter of the largest part of the head portion is between 350μm and 2500 μm.
 3. The system of claim 1, wherein the elongate deliverymember extends through at least a portion of the lumen.
 4. The system ofclaim 1, wherein each of the stents is composed of titanium.
 5. Thesystem of claim 1, wherein a surface material of each of the stentscomprises heparin.
 6. The system of claim 1, wherein the handpiece ofthe delivery device further comprises an actuator configured to causedeployment of the plurality of stents from the delivery device.
 7. Thesystem of claim 1, wherein the stents are preloaded on the elongatedelivery member.
 8. A method of treating an ocular disorder in apatient, the method comprising: providing an anesthetic to an eye of thepatient; forming a corneal incision in the eye of the patient; insertingan elongate delivery member of a delivery device through the cornealincision and advancing a distal tip of the elongate delivery memberwithin an anterior chamber of the eye toward a desired implantationsite, wherein the elongate delivery member comprises a plurality ofglaucoma stents, wherein each of the plurality of glaucoma stentscomprises a tapered base portion, an intermediate waist portion, and ahead, wherein the tapered base portion comprises a plurality of outletports, wherein a minimum cross-sectional diameter of the head is greaterthan a maximum cross-sectional diameter of the tapered base portion; andcausing a tapered base portion of a first glaucoma stent of theplurality of glaucoma stents to be delivered through trabecular meshworkand into a Schlemm's canal of the eye with the head of the firstglaucoma stent remaining in the anterior chamber, thereby facilitatingflow of aqueous through the first glaucoma stent from the anteriorchamber to the Schlemm's canal.
 9. The method of claim 8, furthercomprising withdrawing the delivery device from the eye.
 10. The methodof claim 8, wherein a depth of the waist portion is approximately equalto a thickness of the trabecular meshwork.
 11. The method of claim 8,wherein the minimum cross-sectional diameter of the head is the same asa maximum cross-sectional diameter of the head such that the diameter ofthe head is uniform.
 12. The method of claim 11, wherein the uniformdiameter of the head is between 300 μm and 2750 μm.
 13. A method oftreating an ocular disorder in a patient, the method comprising:inserting an elongate delivery member of a delivery device through anincision in an eye and advancing a distal tip of the elongate deliverymember within an anterior chamber of the eye toward a desiredimplantation site, wherein the elongate delivery member comprises aplurality of stents, wherein each of the plurality of stents comprises atapered base portion, an intermediate waist portion, and a head, whereinthe tapered base portion comprises a plurality of outlet ports, whereina minimum cross-sectional diameter of the head is greater than a maximumcross-sectional diameter of the tapered base portion; and causing atapered base portion of a first stent of the plurality of stents to bedelivered through trabecular meshwork and into a Schlemm's canal of theeye with the head of the first stent remaining in the anterior chamber,thereby facilitating flow of aqueous through the first stent from theanterior chamber to the Schlemm's canal.
 14. The method of claim 13,further comprising withdrawing the delivery device from the eye.
 15. Themethod of claim 13, wherein a depth of the waist portion isapproximately equal to a thickness of the trabecular meshwork.
 16. Themethod of claim 13, wherein the minimum cross-sectional diameter of thehead is the same as a maximum cross-sectional diameter of the head suchthat the diameter of the head is uniform.
 17. The method of claim 16,wherein the uniform diameter of the head is between 300 μm and 2750 μm.